The questions we
hear most.

An ADU (accessory dwelling unit) is a second residence attached to or inside your existing home — usually a basement or garage conversion, or an addition. A DADU is a freestanding building on the same lot. DADUs offer more privacy and a separate entrance from the street side; attached ADUs are typically faster and less expensive because they reuse the existing structure.

Yes. Washington State House Bill 1337, in force across most cities including Seattle, removed the owner-occupancy requirement for ADUs and DADUs. You can rent out both your primary home and your ADU separately. Local rules still govern setbacks, height, and design — we handle those during the permit phase.

Most Washington jurisdictions now allow up to 1,000 square feet for an ADU or DADU, with additional height allowances (typically up to 24 feet for a DADU) when the design includes a habitable upper floor. Maximum sizes depend on lot size and zone — we run a feasibility review before any design work begins.

Most attached ADUs (basement and garage conversions) fall between $200,000 and $400,000 depending on existing conditions, finishes, and the scope of structural and MEP work required. New-construction DADUs typically run from $400,000 to $700,000+. We provide a written, itemized estimate after a site walk so you can compare apples to apples.

We offer both fixed-price and cost-plus contracts. Most clients prefer fixed-price with a written allowance schedule for finish selections, which keeps the contract clean while leaving room for design choices. We're happy to walk through both structures during your initial consultation.

Plan on six to nine months from signed contract to final inspection for an attached ADU, and nine to fourteen months for a DADU. Permitting accounts for a meaningful portion of that timeline — Seattle SDCI averages 8–16 weeks for an ADU permit depending on review queue and any corrections required.

Plan on nine to fourteen months from signed contract to final inspection for a new-construction DADU, depending on lot conditions, size, and finish complexity. Excavation, foundation, and framing front-load the schedule; permitting and any SEPA review can add time before we mobilize. We give you a master schedule before construction starts and update it weekly.

We collaborate with architects and designers, and we have in-house drafting for simpler projects. For ADUs and conversions, we can often handle design coordination directly. For larger projects or anything requiring formal architectural plans, we work with a short list of architects we trust.

Yes. Jet City ADU is a licensed, bonded, and insured general contractor in Washington State. We carry general liability and workers' compensation coverage on all employees and trades. License and bond information is available on request.

Yes. We run a small number of projects at a time so the same lead carpenter and project manager are on your job from start to finish. You'll know who's on site, you'll have a direct line, and you'll get weekly written updates.

We work throughout King and Snohomish counties — Seattle, Bellevue, Kirkland, Redmond, Woodinville, Bothell, Edmonds, Lynnwood, Mukilteo, Mill Creek, Snohomish, Mercer Island, and the surrounding communities. For projects outside this radius, please reach out and we'll let you know if we can take it on.

Call (206) 207-2044 or email aduseattle@gmail.com with a few sentences about your project, your address, and any plans or inspiration you already have. We'll schedule a no-cost site walk, and within a week of that visit you'll have a written, itemized estimate.